Overview

svdir is a Ruby interface to the “service directory” style of robust daemon process supervision introducted in Dan Bernstein’s daemontools software and compatibly extended in Gerit Pape’s runit package.

It exposes a programmatic interface to reliably starting, stopping, signalling and interrogating services all implemented directly – no need to shell out to separate utilities. See the documentation for Sys::Sv::SvDir for complete information.

More information on daemontools is available at cr.yp.to/daemontools.html. More information on runit is available at smarden.org/runit/.

Example

The example/ subdirectory in the source distribution contains a demonstration program which a system adminstrator might use to control daemons.

Typical programmatic use of this software might look like this:

#! /usr/bin/env ruby

require 'sys/sv/svdir'
include Sys::Sv

# shut down all daemons running under /service
Dir["/service"].each do |svpath|
  s = SvDir.new(svpath)

  # force the .../log to shut down, ignoring services without loggers
  s.log.signal(:exit) rescue nil

  pid = s.pid
  if pid != 0
  	s.signal(:exit)
    puts "Told #{s.path} (pid #{pid}) to exit"
  end
end

Installation

Look for the gem on rubygems.org.

‘rake package` will build a .gem under pkg/, and `rake rdoc` will generate module documentation.

‘rake test` and `rake rcov` will give a good idea of where the code is.

To Do

Further testing
- log()
- TAI64 testing
Possible extensions
- SvDir.new(d) &block - persist StatusBytes object for block?
- normally_down! and normally_up!

Author

Mike Pomraning (“mpomraning” at “qualys” dot “com”)